Tyler Weaver
updated chan_fatfs
Fork of
chan_fatfs
by 
Eli Hughes
Diff: diskio.cpp
- Revision:
- 2:e8cd708f09ff
- Parent:
- 1:68378811b1e2
- Child:
- 4:f88948891a05
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/diskio.cpp Tue Dec 11 21:46:00 2012 +0000
@@ -0,0 +1,440 @@
+/*-----------------------------------------------------------------------*/
+/* Low level disk I/O module skeleton for FatFs (C)ChaN, 2007 */
+/*-----------------------------------------------------------------------*/
+/* This is a stub disk I/O module that acts as front end of the existing */
+/* disk I/O modules and attach it to FatFs module with common interface. */
+/*-----------------------------------------------------------------------*/
+
+#include "diskio.h"
+#include "mbed.h"
+#include "mbed_debug.h"
+
+
+//******************************************************************************************************************
+// MBED SPI/CS Select functions.... Modify for your layout.
+//**************************************************************************************
+
+SPI _spi(p5, p6, p7); // mosi, miso, sclk
+DigitalOut _cs(p8);
+
+//******************************************************************************************************************
+// Low Level Sector Access Function Prototypes('C' Castrated versions of Simon Ford's C++ MBED SDFileSystem class
+//******************************************************************************************************************
+int _cmd(int cmd, int arg);
+int _read(BYTE *buffer, int length);
+int _write(BYTE *buffer, int length);
+uint32_t ext_bits(BYTE *data, int msb, int lsb);
+int _sd_sectors();
+int _sectors;
+int _cmd(int cmd, int arg);
+int _cmdx(int cmd, int arg);
+int _cmd8();
+int _cmd58();
+int cdv;
+
+#define SD_COMMAND_TIMEOUT 5000
+
+#define R1_IDLE_STATE (1 << 0)
+#define R1_ERASE_RESET (1 << 1)
+#define R1_ILLEGAL_COMMAND (1 << 2)
+#define R1_COM_CRC_ERROR (1 << 3)
+#define R1_ERASE_SEQUENCE_ERROR (1 << 4)
+#define R1_ADDRESS_ERROR (1 << 5)
+#define R1_PARAMETER_ERROR (1 << 6)
+
+
+//******************************************************************************************************************
+// Sector Access functions for CHAN FatFs
+//******************************************************************************************************************
+
+DRESULT disk_ioctl (
+ BYTE drv, /* Physical drive nmuber (0..) */
+ BYTE ctrl, /* Control code */
+ void *buff /* Buffer to send/receive control data */
+)
+{
+ DRESULT res;
+
+ switch(ctrl) {
+ case CTRL_SYNC:
+ res = RES_OK;
+ break;
+
+ case GET_SECTOR_SIZE:
+ res = RES_OK;
+ *(WORD *)buff = 512;
+ break;
+
+ case GET_SECTOR_COUNT:
+ res = RES_OK;
+ *(DWORD *)buff = (WORD)_sd_sectors();
+ break;
+
+ case GET_BLOCK_SIZE:
+ res = RES_OK;
+ *(DWORD *)buff = 1;
+ break;
+
+ default:
+ res = RES_OK;
+ break;
+ }
+ return res;
+}
+
+DSTATUS disk_initialize(BYTE Drive)
+{
+ // Set to 100kHz for initialisation, and clock card with cs = 1
+ _spi.frequency(100000);
+ _cs = 1;
+ for (int i = 0; i < 16; i++) {
+ _spi.write(0xFF);
+ }
+
+ // send CMD0, should return with all zeros except IDLE STATE set (bit 0)
+ if (_cmd(0, 0) != R1_IDLE_STATE) {
+ debug("No disk, or could not put SD card in to SPI idle state\n");
+ return STA_NOINIT;
+ }
+
+ // send CMD8 to determine whther it is ver 2.x
+ int r = _cmd8();
+ if (r == R1_IDLE_STATE) {
+ for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
+ wait_ms(50);
+ _cmd58();
+ _cmd(55, 0);
+ if (_cmd(41, 0x40000000) == 0) {
+ _cmd58();
+ //debug_if(SD_DBG, "\n\rInit: SDCARD_V2\n\r");
+ cdv = 1;
+ return 0;
+ }
+ }
+ debug("Timeout waiting for v2.x card\n");
+ return STA_NOINIT;
+
+ } else if (r == (R1_IDLE_STATE | R1_ILLEGAL_COMMAND)) {
+ for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
+ _cmd(55, 0);
+ if (_cmd(41, 0) == 0) {
+ cdv = 512;
+ //debug_if(SD_DBG, "\n\rInit: SEDCARD_V1\n\r");
+ return 0;
+ }
+ }
+ debug("Timeout waiting for v1.x card\n");
+ return STA_NOINIT;
+
+ } else {
+ debug("Not in idle state after sending CMD8 (not an SD card?)\n");
+ return STA_NOINIT;
+ }
+
+ _sectors = _sd_sectors();
+
+ // Set block length to 512 (CMD16)
+ if (_cmd(16, 512) != 0) {
+ debug("Set 512-byte block timed out\n");
+ return STA_NOINIT;
+ }
+
+ _spi.frequency(10000000); // Set to 10MHz for data transfer
+ return 0;
+}
+
+DRESULT disk_write(BYTE Drive,const BYTE * Buffer, DWORD SectorNumber, BYTE SectorCount)
+{
+ BYTE i;
+
+ BYTE * MyBufOut = (BYTE *)Buffer;
+
+ for(i=0; i<SectorCount; i++) {
+ // set write address for single block (CMD24)
+ if(_cmd(24, (SectorNumber + i) * 512 ) != 0) {
+ return RES_ERROR;
+ }
+
+ // send the data block
+ _write(MyBufOut, 512);
+
+ MyBufOut+=512;
+ }
+ return RES_OK;
+}
+
+DRESULT disk_read(BYTE Drive, BYTE * Buffer,DWORD SectorNumber, BYTE SectorCount)
+{
+ BYTE i;
+ for(i=0; i<SectorCount; i++) {
+ // set read address for single block (CMD17)
+ if(_cmd(17, (SectorNumber+i) * 512) != 0) {
+ return RES_ERROR;
+ }
+ // receive the data
+ _read(Buffer, 512);
+
+ Buffer+=512;
+ }
+ return RES_OK;
+}
+
+
+DWORD get_fattime(void)
+{
+ time_t CurrentTimeStamp;
+ tm *CurrentLocalTime;
+ DWORD FATFSTimeCode;
+
+ CurrentTimeStamp = time(NULL);
+ CurrentLocalTime = localtime(&CurrentTimeStamp);
+
+ //Map the tm struct time into the FatFs time code
+ FATFSTimeCode = ((CurrentLocalTime->tm_year-80)<<25) |
+ ((CurrentLocalTime->tm_mon+1)<<21) |
+ ((CurrentLocalTime->tm_mday)<<16) |
+ ((CurrentLocalTime->tm_hour)<<11) |
+ ((CurrentLocalTime->tm_min)<<5) |
+ ((CurrentLocalTime->tm_sec));
+
+ return FATFSTimeCode;
+}
+
+DSTATUS disk_status(BYTE Drive)
+{
+ return 0;
+}
+
+//**************************************************************************************
+// Low Level Sector Access Functions (Castrated versions of Simon Fords C++ MBED class
+//**************************************************************************************
+
+int _cmd(int cmd, int arg)
+{
+ _cs = 0;
+
+ // send a command
+ _spi.write(0x40 | cmd);
+ _spi.write(arg >> 24);
+ _spi.write(arg >> 16);
+ _spi.write(arg >> 8);
+ _spi.write(arg >> 0);
+ _spi.write(0x95);
+
+ // wait for the repsonse (response[7] == 0)
+ for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
+ int response = _spi.write(0xFF);
+ if (!(response & 0x80)) {
+ _cs = 1;
+ _spi.write(0xFF);
+ return response;
+ }
+ }
+ _cs = 1;
+ _spi.write(0xFF);
+ return -1; // timeout
+}
+int _cmdx(int cmd, int arg)
+{
+ _cs = 0;
+
+ // send a command
+ _spi.write(0x40 | cmd);
+ _spi.write(arg >> 24);
+ _spi.write(arg >> 16);
+ _spi.write(arg >> 8);
+ _spi.write(arg >> 0);
+ _spi.write(0x95);
+
+ // wait for the repsonse (response[7] == 0)
+ for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
+ int response = _spi.write(0xFF);
+ if (!(response & 0x80)) {
+ return response;
+ }
+ }
+ _cs = 1;
+ _spi.write(0xFF);
+ return -1; // timeout
+}
+
+
+int _cmd58()
+{
+ _cs = 0;
+ int arg = 0;
+
+ // send a command
+ _spi.write(0x40 | 58);
+ _spi.write(arg >> 24);
+ _spi.write(arg >> 16);
+ _spi.write(arg >> 8);
+ _spi.write(arg >> 0);
+ _spi.write(0x95);
+
+ // wait for the repsonse (response[7] == 0)
+ for (int i = 0; i < SD_COMMAND_TIMEOUT; i++) {
+ int response = _spi.write(0xFF);
+ if (!(response & 0x80)) {
+ int ocr = _spi.write(0xFF) << 24;
+ ocr |= _spi.write(0xFF) << 16;
+ ocr |= _spi.write(0xFF) << 8;
+ ocr |= _spi.write(0xFF) << 0;
+ _cs = 1;
+ _spi.write(0xFF);
+ return response;
+ }
+ }
+ _cs = 1;
+ _spi.write(0xFF);
+ return -1; // timeout
+}
+
+int _cmd8()
+{
+ _cs = 0;
+
+ // send a command
+ _spi.write(0x40 | 8); // CMD8
+ _spi.write(0x00); // reserved
+ _spi.write(0x00); // reserved
+ _spi.write(0x01); // 3.3v
+ _spi.write(0xAA); // check pattern
+ _spi.write(0x87); // crc
+
+ // wait for the repsonse (response[7] == 0)
+ for (int i = 0; i < SD_COMMAND_TIMEOUT * 1000; i++) {
+ char response[5];
+ response[0] = _spi.write(0xFF);
+ if (!(response[0] & 0x80)) {
+ for (int j = 1; j < 5; j++) {
+ response[i] = _spi.write(0xFF);
+ }
+ _cs = 1;
+ _spi.write(0xFF);
+ return response[0];
+ }
+ }
+ _cs = 1;
+ _spi.write(0xFF);
+ return -1; // timeout
+}
+int _read(BYTE *buffer, int length)
+{
+ _cs = 0;
+
+ // read until start byte (0xFF)
+ while (_spi.write(0xFF) != 0xFE);
+
+ // read data
+ for (int i = 0; i < length; i++) {
+ buffer[i] = _spi.write(0xFF);
+ }
+ _spi.write(0xFF); // checksum
+ _spi.write(0xFF);
+
+ _cs = 1;
+ _spi.write(0xFF);
+ return 0;
+}
+
+
+int _write(BYTE *buffer, int length)
+{
+ _cs = 0;
+
+ // indicate start of block
+ _spi.write(0xFE);
+
+ // write the data
+ for (int i = 0; i < length; i++) {
+ _spi.write(buffer[i]);
+ }
+
+ // write the checksum
+ _spi.write(0xFF);
+ _spi.write(0xFF);
+
+ // check the response token
+ if ((_spi.write(0xFF) & 0x1F) != 0x05) {
+ _cs = 1;
+ _spi.write(0xFF);
+ return 1;
+ }
+
+ // wait for write to finish
+ while (_spi.write(0xFF) == 0);
+
+ _cs = 1;
+ _spi.write(0xFF);
+ return 0;
+}
+
+static uint32_t ext_bits(unsigned char *data, int msb, int lsb)
+{
+ uint32_t bits = 0;
+ uint32_t size = 1 + msb - lsb;
+ for (int i = 0; i < size; i++) {
+ uint32_t position = lsb + i;
+ uint32_t byte = 15 - (position >> 3);
+ uint32_t bit = position & 0x7;
+ uint32_t value = (data[byte] >> bit) & 1;
+ bits |= value << i;
+ }
+ return bits;
+}
+
+int _sd_sectors()
+{
+ uint32_t c_size, c_size_mult, read_bl_len;
+ uint32_t block_len, mult, blocknr, capacity;
+ uint32_t hc_c_size;
+ uint64_t blocks;
+
+ // CMD9, Response R2 (R1 byte + 16-byte block read)
+ if (_cmdx(9, 0) != 0) {
+ debug("Didn't get a response from the disk\n");
+ return 0;
+ }
+
+ uint8_t csd[16];
+ if (_read(csd, 16) != 0) {
+ debug("Couldn't read csd response from disk\n");
+ return 0;
+ }
+
+ // csd_structure : csd[127:126]
+ // c_size : csd[73:62]
+ // c_size_mult : csd[49:47]
+ // read_bl_len : csd[83:80] - the *maximum* read block length
+
+ int csd_structure = ext_bits(csd, 127, 126);
+
+ switch (csd_structure) {
+ case 0:
+ cdv = 512;
+ c_size = ext_bits(csd, 73, 62);
+ c_size_mult = ext_bits(csd, 49, 47);
+ read_bl_len = ext_bits(csd, 83, 80);
+
+ block_len = 1 << read_bl_len;
+ mult = 1 << (c_size_mult + 2);
+ blocknr = (c_size + 1) * mult;
+ capacity = blocknr * block_len;
+ blocks = capacity / 512;
+ //debug_if(SD_DBG, "\n\rSDCard\n\rc_size: %d \n\rcapacity: %ld \n\rsectors: %lld\n\r", c_size, capacity, blocks);
+ break;
+
+ case 1:
+ cdv = 1;
+ hc_c_size = ext_bits(csd, 63, 48);
+ blocks = (hc_c_size+1)*1024;
+ //debug_if(SD_DBG, "\n\rSDHC Card \n\rhc_c_size: %d\n\rcapacity: %lld \n\rsectors: %lld\n\r", hc_c_size, blocks*512, blocks);
+ break;
+
+ default:
+ debug("CSD struct unsupported\r\n");
+ return 0;
+ };
+ return blocks;
+}
\ No newline at end of file